The embodiments described herein relate to apparatus and methods for treating leaks within a stent graft. More particularly, the embodiments described herein relate to apparatus and methods for treating a type 2 endoleak from within an endoluminal stent graft.
Abdominal aortic aneurysms (AAA) are a common form of cardiovascular disease and often treated with an endoluminal stent graft. Such known treatments include inserting a catheter into the femoral artery of a patient and placing an endoluminal stent graft (also referred to herein as an “ELG”) at the location of the aneurysm. Once in place, the ELG is expanded, creating a snug fit with the aortic walls above and below the aneurysm. In such known procedures, the ELG relieves the pressure on the weakened arterial walls at the location of the aneurysm.
In some instances, endoluminal stent grafts can develop leaks such that blood flow leaks through a given portion of the ELG and into the aneurysm sac (e.g., a type 1 endoleak). In some instances, the aneurysm sac may remain pressurized from blood flowing into the sac from the lumbar or inferior mesenteric arteries even though the ELG has been placed successfully and remains intact without holes or leaks at the seal points (e.g., a type 2 endoleak). Type 2 endoleaks occur when blood flow takes a circuitous route traveling through branches from the non-stented portion of the aorta through anastomotic connections into collateral vessels with a direct communication with the aneurysmal sac. Blood can then travel in a retrograde direction in these collateral vessels, eventually emptying into the sac behind the stent-graft. These collateral vessels, prior to aortic exclusion via the stent-graft, carry blood from the aorta to nutrient beds of lower pressure. When the aorta from which they originate is excluded, the pressure gradient favors flow in the opposite direction.
In such instances, the aneurysm sac can grow in size and thus, the chance for rupture and internal bleeding exists. Known treatments for sealing endoleaks exist and vary with the type and severity of the endoleak. For example, translumbar embolization is a known treatment for type 2 endoleaks. Such procedures require the precise puncture of the aneurysm sac at the endoleak location. More specifically, image guidance techniques are used to guide a needle during insertion through the back of a patient to the aneurysm location. Once at the target location, the position of the needle is verified and the aneurysm sac is punctured. With the aneurysm sac punctured, the needle is positioned at the endoleak location and an embolic agent can be injected into the aneurysm sac to seal the endoleak. Another method of treating a type 2 endoleak is using an endovascular technique, which involves threading a catheter through the connecting arteries that supply blood flow into the aneurysm sac. Once the catheter reaches the sac, the sac and feeding arteries can be embolized sealing the endoleak.
Difficulties of a translumbar embolization procedure include the physician, technician, surgeon, etc., carefully avoiding organs within the body, placing the needle at a precise location to puncture the aneurysm sac, and embolizing at a precise location of the endoleak while carefully avoiding the puncture of the ELG. Difficulties of the endovascular procedure include difficulty threading the catheter through extremely small and tortuous blood vessels in order to reach the blood flow within the aneurysm sac, extremely long procedure times exposing physician and patient to higher radiation doses, and high technical failure rates due to inability to reach the aneurysm sac.
Thus, a need exists for improved apparatus and methods for intra-arterially treating a type 2 endoleak of an ELG.